Yamaha DTXpress/DTXplorer/DTXtreme

ive owned my dtxIII special for about 3 months now and im very happy 
with it. however i still have three issues that i cant seem to resolve:

1. to get the full closed sound on the hh, i must press really hard on 
the pedal (i wish the weight of my foot would be enough...)
(ive played around with the clutch and trigger settings with no luck)

2. my crash (the two-zone chokeable one)will sometimes not register a 
hit. i can hit it very soft to extremely hard and most of the time it 
produces a sound...but every once in a while it will fail...(is there 
a "dead" zone between the rim zone and the larger zone?)

3. even rarer than the crash "miss" is an unusually loud snare hit. i 
play about an hour a day and maby once a week my snare will produce a 
very loud sound (louder than i can possibly produce on purpose)

any help is greatly appreciated.
thanks,